The present invention relates to the vacuum cleaner arts. More particularly, the present invention relates to upright vacuum cleaners that are used for suctioning dirt and debris from carpets and floors.
Upright vacuum cleaners are well known in the art. Two types of upright vacuum cleaners are a soft bag-type vacuum cleaner and a hard shell-type vacuum cleaner. In a conventional soft bag-type vacuum cleaner, a vacuum source generates the suction required to pull dirt from the carpet or floor being vacuumed through a suction opening, through a motor/fan housing, and into a filter bag housed within a soft bag secured to a handle portion of the vacuum cleaner. The cleaned air is then exhausted through the porous walls of the filter bag and soft bag. In a conventional hard shell-type vacuum cleaner, a vacuum source generates the suction required to pull dirt from the carpet or floor being vacuumed through a suction opening and into a filter bag housed within a hard shell upper portion of the vacuum cleaner. Cleaned air travels through the porous walls of the filter bag, through the motor/fan housing, and is then exhausted to the atmosphere.
To avoid the need for vacuum filter bags altogether, and the associated expense and inconvenience of replacing filter bags, a third type of upright vacuum cleaner utilizes cyclonic airflow, rather than a filter bag, to separate the majority of the dirt and other particulates from the suction air stream. After separating debris from the air stream, the air is typically filtered to remove any residual particulates. The filtered air then travels through the motor/fan housing and is exhausted.
For many of the known cyclonic airflow-type vacuum cleaners, the process of emptying a dirt collection container is inconvenient and often results in the spillage of the container contents. Further, in some cyclonic airflow-type vacuum cleaners, the exhaust air is not sufficiently free of residual contaminants. Because the cyclonic action of such conventional cyclonic airflow-type vacuum cleaners does not completely remove all dust, dirt and other contaminants from the suction air stream, it is necessary to include an exhaust filter downstream from the motor. As a result, some cyclonic airflow-type vacuum cleaners incorporate a final filter stage such as a substantially rectangular or cartridge-type exhaust filter positioned on one side of the vacuum cleaner upright housing section. Such cyclonic airflow-type vacuum cleaners incorporating cartridge-type exhaust filters tend to have profiles that are bulky and less maneuverable for the user.
Accordingly, it has been deemed desirable to develop a new and improved upright vacuum cleaner having an optimized airflow pathway that overcomes the foregoing difficulties and others while providing better and more advantageous overall results.